[Yaesu] Ft1kMP loss of receive gain

[G3SJJ]

I am noticing a receive loss of around 10-12 dB. I have checked Antenna 
B and receive antenna inputs. They are the same.

What I do notice is around 2-4 s units difference in indicated signal 
strength between main and sub Rx, which would indicate the problem is 
after the 1st mixer.

We recently used the radio as a spotter in CQWW CW at G5W . Whilst it is 
unlikely, we could have zapped the front end somewhere.

Anyone got any thoughts?

Chris G3SJJ